Process of printing on vitrified ware



J. F. KELLY.

PROCESS OF PRINTING 0N VITRIFIED WARE.

APPLICATION Fl LED OCT. 24. 1921.

1,433,892; 7 Patented 001:. 31, 1922..

I INVEWLDV:

Patented @ot. m, 1922 JAMES F. KELLY, OF NEWTON, MASSACHUSETTS, ASSIGNQRT OHARA WALTHAJTI DIAL CO. INC., 0F WALTHAM, MASSACHUSETTS, ACORPORATIGN 0F MASSACHU- SETTS.

PROCESS OF PRINTING 0N 'VITRIFIED WARE.

Application file d Uetober 24, 1921. Serial No. 509,848.

To all whom it may concern:

Be it known that I, JAMEs F. KELLY, a citizen of the United States,residingI at Newton, county of Middlesex, State of l assachusetts, haveinvented a certain new and useful Improvement in Processes of Printingon Vitrified Ware, of which the following is a specification, referencebeing had therein to the accompanying drawings.

The invention relates to a new and useful improvement in process ofprinting on vitrified ware. Tt is especially intended for application toenamel dials but it is adapted for use in printing on any kind of anarticle made '15 of vitrified ware, such for instance as porcelain,enamel, china, pottery, glass, or any other kind of vitrified article,and the-claims are intended to cover application to any such kind ofarticles. The term printing 2c is intended to be used in a broad sense,

whether letters, figures, or any decorative design.

The invention is more particularly intended for application in theprinting of White.

' or light-colored lettering, marking, or design on a dark background.

Heretofoie, so far as I am aware, it has been possible to make inquantity such an article having light-colored lettering or marking on adark background only by exensive photographic process, although aight-colored dial with dark letters has been made by the so-calledoffset process.

The reason that light printing cannot be 5 satisfactorily put on a darkbackground in the same way that a dark print can be put on a lightbackground, is that light colors cannot be made opaque enough so thatthe dark background will not show through.

The invention will be fully understood from the following descriptionwhen taken in connection with the accompanying drawings, and the novelfeatures thereof will be pointed out and clearly defined in the claims4.5 at the close of this specification.

In the drawings, Fig. 1 is a perspective view of an enameled articlewhich is to be marked.

Fig. 2 is a plan view of the article after so the color resist has beenapplied in the form of the design.

Fig. 3 is a diagram representing a section on line 3 of Fig. 2

and 3).

Fig. 4 is a view similar to Fig. 3 after the ummy substance constitutingthe vehicle or the coloring matter has been applied.

Fig. 5 is a view similar to Fig. 4 after the coloring matter has beenapplied.

Fig. 6 is a view similarto Fig. 5 after the article has-been fired andbefore the heat resist and the coloring matter superimposed over it hasbeen brushed oil, the gum having vanished by the firing.

Fig. 7 is a plan View of the finished article after it has been firedand that portion 'of the coloring which was laid over the resist and theresist itself are both rubbed off.

Fig. 8 is a diagram representing a section on line 8, 8 of Figure 7.

In all the views, the thickness of the coatings is shown greatlyexaggerated, especially the gum which is very much exaggerated.

Referring now to the drawings, 1 represents a porcelain or enamelarticle which is to be decorated or lettered by my improved process. Forsimplicity of lllustration, the article 1 is shown as a small plate. Theblank as shown at 1 may be of ordinary porcelain having an enamelsurface 2 and made in exactly the same way as in the case of an ordinarywhite dial, that is, with a plain white surface.

lln' carrying out my invention, as the first step in the process, theform of lettering or other, marking desired is marked on there? enamelsurface by the use of a heat resisting substance 3 which will behereinafter re ferred to as the heat resist. (See Figs. 2 This heatresist consists of some material which has a very much higher meltingpoint than the enamel of which the artie ole is made or of the'minera'lcoloring 5 hereinafter referred to. It can have for a basis, chalk,whiting, zinc oxide, finely ground quartz, or any other powder wlnch hasa high melting point. This heat resist is made into a paint. As avehicle for making this powder into the paint, any of the usual oils canbe employed. Some of these oils are fat oil of turpentine, Canadabalsam, Venice turpentine, oil of thyme, lavender oil, or any group ofthese in appropriate proportions. The'above enumerated oils are merelyillustrative. Any other suitable oils or gums may be employed. lit ispreierableto a small touch of lamp black in this he- Mill surface.

shown at 3, by any suitable process of which there are many in use.' Ihave had the best.

success by the use of the oil'set dial painting process, so-called. g

After the lettering has been applied, as above described, the backgroundor dark color of the article is put on'by the following means :-'A verylight coat 4 of sticky gum of some kind is applied over the entiresurface of the article; the preferred method of applying it is byspraying. For this urpose, the gum employed is gum mastic, anada balsam,or any other sort of oil or gum which will turn to gas at the firingtemperature. (See Figure l.)-

While this coating of gum or oil is still in a tacky state, a finelyground black or dark mineral coloring 5 is sifted onto the tacky (SeeFigure 5.) A suitable mineral coloring for this purpose is what is known"to the trade as enamelers oxides or china decorating colors. A thincoat of the mineral coloring will stick to the gum. Any excess can bebrushed ofi with a fine brus such, for instance, as'a camels-hair brush.The article is now ready to be fired. The preferred method of firing isto put it in a mufile furnaceat from 1200 to 1800 Fahrenheit until thedark or black mineral color which has been dusted on is fused into a.uniform coat. {j

The heat resist 3, previously referred to, with which the lettering ordesign was marked out, serves to insulate the white metal backgroundcovered b said heat resist, so that the mineral coloring will not adhereto thatportion covered by the heat resist. Where it is not so insulated,the mineral coloring will adhere firmly and uniformly to the surface. Itwill not adhere to the portioncovered by the heat resist paint becausethe said resist paint consists mainly of heat resisting powder whichwill not melt at the firing temperature, and therefore the darkvitrified mineral color for the background does not adhere to thewhite-surface covered by the resist aint.

The resist powder b oils or ot er vehicle contained in the resist paintwill evaporate. (See Figure 6.) The dark colored mineral paintsuperimposed over the resist paint and which has there been insulatedfrom the white background, can easily be brushed ofi', leaving the whiteor light colored markings of the same design as originally printed onthe article by the paint will be turned to a dry the heat of the firing,.and the.

enace heat resist paint, and theremainingsurface the firing temperature,then applying a thin coat-of mineral coloring onto the tacky sur-- face,then firing the article at a sufiiciently hi h degree of heat a fuse themineral co oring, and then removing the heat resist substance which wasfirst applied in laying out the design forthe marking as any mineralcoloring which adheres thereto.

2. The process of printing onvitrified ware consisting of applying tothe surface of the article a, heat resist substance in the form of adesign with which the article is to be marked, said heat resistsubstance having a higher melting point than the enamel surface of thearticle, then spreading over the surfaceof the article a coat of stickysubstance having .the characteristic that it will turn to gas at thefiring temperature, then applying a coat of mineral coloring to thetacky surface made by the sticky substance,

then firing the article at a sufficiently high for the marking,therebyleaving the article with a background formed by the fused mineralcoloring and with an exposed portion of the original vitrified surfacein the form of design which was marked out with the heat resistsubstance.

3. The process of printing on vitrified ware consisting 'of marking uponthe vitrified surface of the article the desired design with a heatresist substance which has a higher melting point than the vitrifiedsurface of the article, then applying to the surface of the article acoat of sticky substance having the characteristic that it will turn togas at the firing temperature, then applying a coat of mineral coloringto the tacky surface made by the sticky substance, then firing thearticle in a muflle furnace at a temperature high enough for the mineralcoloring matter to be fused into a uniform coat, and then removing thecolor resist substance and'any' surface matter which may adhere thereto.

4:.Tl16 process of printing on vitrified ware consisting of marking uponthe surface of the article! the form of the desired mark with asubstance which will not melt at the fusing point of the vitrifiedarticle, then apits aeaeea plying to the enamel surface of the article asubstance which has the characteristic 01. disappearing at the fusingtemperature, then applyinga coat of fusible coloring substance andfiring the article to a sufficient degree to fuse the coloringsubstance, and then removing the substance with which the design wasfirst marked out.

5. The process of printing on vitrified ware consisting of marking uponthe surface of the article the form of the desired mark with a substancewhich will not melt at the fusing point of the vitrified article, thenapplying to the surface of the article a coat of fusible coloring matterby means of a vehicle which has the characteristic of disappearing atthe fusing temperature, then firing the article to a sufiicient degreeto use the coloring substance, and then removing the substance withwhich the design was first marked out,

In. testimony whereof I afiix my signature.

JAMES F. KELLY.

